Ross - proof of yours and mine being a 'letter-weight' or paperweight - a malachite coloured (and swirled pattern design ) item in the same shape as ours with the knop handle
http://www.sellingantiques.co.uk/253672/late-victorian-porcelain-desk-paperweight/proof in the sense that the particular piece has a label. Seller says the label reads:
Waterson Bros. & Layton, Law & General Stationers, 23, 24 & 25 Birchen Lane, London"
I think the seller may have the maker wrong in that the label is hard to read and I found a reference to
'Water
low Bros. and Layton'
Graces says:
1877 James Waterlow's business was divided by his heirs; two of the sons, with other members of the family and Mr. A. T. Layton, established the firm of Waterlow Brothers and Layton; Sir Sydney Waterlow and his sons, together with his brother Walter and some of their most experienced colleagues, continued as Waterlow and Sons.
Specialized on the legal and country side of the business.
1887 The company was registered on 8 January, to acquire the business of the firm of the same name, as stationers, printers.
1893 On 2 August, re-registration was effected under the same title in connection with an increase of the capital. [1]
1920 Merged into Waterlow and Sons
http://www.gracesguide.co.uk/Waterlow_Brothers_and_Laytonseller also says
'(Birchen Lane is in the heart of the City). 'So his is possibly post 1877 and pre 1920 (when the company merged into Waterlow and Sons).
However the Waterlow company goes back to 1810, so ours might be earlier (and his might be earlier - acquisitions and labels don't always coincide on dates)
https://en.wikipedia.org/wiki/Waterlow_and_SonsStill don't know what that is made of - should think not porcelain unless porcelain is known to be heavy?
but the base of his also shows the glaze. So wondering what 'earth' mine is made from?